I would make the food, cool it, and then add the plantain flour, the way thickener is normally added to gravy after cooking, so as to minimize heating and thus maximize the RS. If you cook the plantain flour itself, you will greatly reduce the RS.
I learned in the past from experience that the tastiest dried foods involve the least heat possible, with air-drying being best. I dry foods on a dehydrator drying rack in the fridge. Thus, they are cooled while drying, rather than heated, as in a dehydrator machine, which I never use any more (even at the lowest setting, the tastiness of the foods is reduced). I found that the longer I air-dry plantain slices, the slightly tastier they become. I find thoroughly dried plantain slices topped with raw cheese to be pretty enjoyable, and more filling than with ordinary grain crackers that I ate in years past.
Otzi, raw potatoes contain the steroidal glycoalkaloids alpha-chaconine and alpha-solanine and the alkaloid solanidine, which can reportedly be allergenic for some and toxic in excessive amounts. What are your thoughts on these? How much does drying reduce them? I noticed that a small amount of fresh peeled raw potato caused a burning sensation on my tongue. There are even reports of a small number of people dying from excessive consumption of raw potato. Tolerances vary, and my grandfather never reported any discomfort from eating a few slices of raw potato now and then.
Raw plantains are reportedly nontoxic:
As you know, fufu is another traditional staple food that likely contains RS. It can be made using yams, cassava, cocoyam (taro) or plantains, or a mixture. Interestingly, it is traditionally swallowed, rather than chewed, and chewing "is discouraged." http://en.wikipedia.org/wiki/Fufu Since RS doesn't digest in the mouth or stomach, this makes some sense.Banana and plantain
Banana and plantain do not contain significant levels of any toxic principles. They do contain high levels of serotonin, dopamine and other biogenic amines. Dopamine is responsible for the enzymic browning of sliced banana. Serotonin intake at high levels from plantain has been implicated in the aetiology of endomyocardial fibrosis (EMF) (Foy and Parratt, 1960). However, Ojo (1969) has shown that serotonine is rapidly removed from the circulating plasma and so does not contribute to elevated levels of biogenic amines in healthy Nigerians. It has been confirmed by Shaper (1967) that there is insufficient evidence for regarding its level in plantain as a factor in the aetiology of EMF.
Toxic substances and antinutritional factors